This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This proposal describes a research program in the development of versatile photosensitizers excitable by Infrared source for photodynamic therapy (PDT) as applied to breast cancer treatment. PDT utilizes a photosensitizer, working as a light-activated drug, to treat the target tissue locally upon the irradiation of light with appropriate wavelengths. One of the key components in effective and efficient PDT is the photosensitizers, so called PDT drugs. The goal of this study is to design and develop photosensitizers toward improving the efficacy of targeted PDT for breast cancer treatment. This study will focus on the photochemical activity and the targeted therapeutic nature of the photosensitizers. We believe that such photosensitizers could potentially satisfy the requirements of an ideal PDT drug and become the next generation PDT drugs. We expect the advancement of PDT drug development will improve the use of PDT for breast cancer treatment.